function K = center(Ktst,Ktrn) %CENTER Center the kernel matrix % % K = CENTER(KTST,KTRN) % % Center the kernel matrix KTST in the kernelspace defined by KTRN. % %@article{Scholkopf1998, % author = {Bernhard Scholkopf and Alex J. Smola and Klaus-Robert % M{\" u}ller}, % title = {Nonlinear Component Analysis as a Kernel Eigenvalue Problem}, % journal = {Neural Computation}, % year = {1998}, % volume = {10}, % number = {5}, % pages = {1299-1319} %} % Copyright: D.M.J. Tax, D.M.J.Tax@prtools.org % Faculty EWI, Delft University of Technology % P.O. Box 5031, 2600 GA Delft, The Netherlands n = size(Ktrn,1); I = repmat(1/n,n,n); m = size(Ktst,1); I1 = repmat(1/n,m,n); K = Ktst - I1*Ktrn - Ktst*I + I1*Ktrn*I; return
